Method and composition for stabilizing soil and process for making the same

ABSTRACT

A water soluble chemical composition for use as a soil stabilizer,  conditer and structuring agent includes a dispersing agent such as a polyanionic sulfonated urea-melamine formaldehyde condensate, an aggregating agent such as a non-ionic water soluble urea-formaldehyde condensate having relative weight average molecular weights between 400 to 10,000 and polydispersity between 2.5 to 10, and a basic salt like di-sodium tetra borate and/or a neutral salt like sodium chloride and a nitrogen potassium or phosphorous containing compound such as potassium nitrate, phosphoric acid, potassium dihydrogen orthophosphate and the like, wherein the ratio of urea-formaldehyde to sulfonated urea-melamine-formaldehyde is between 0.2:1 to 2.0:1 and the final solid contents of this composition is between 1-15%. These compositions are then sprayed on top of sand or soil with conventional equipment and will impart significant improvements in their mechanical properties and their erosion resistance to water and wind.

FIELD OF THE INVENTION

The present invention relates to soil conditioning compositions, aprocess for making such compositions and a method of using the same. Theinvention relates more particularly to an improved multipurpose softconditioning composition which improves the compressive strength oftreated soil, particularly dune sand, renders the treated soil moreresistant to erosion by water and wind and at the same time enhancesplant growth.

BACKGROUND OF THE INVENTION

Soil or sand erosion by wind and water is a problem in most countries,especially for those with arid climates that are characterized by lowrain fall, high solar radiation, high temperature and high evaporationrates. In such countries, erosion is due to the existence of fine soilparticles on the surface of the soil that are loose and poorly bondedtogether and then susceptible to be blown by the wind resulting in sandstorms, dust clouds and even sand dune movement.

The structure of soil determines its properties such as permeability towater, porosity, crust formation, load-carrying capacity, etc.Therefore, an improved soil structure will reduce soil erosion by windor water. It will also reduce water evaporation, increase intra- andinter particle linkages and increase the bonding strength ofagglomerates so that they can sustain heavy weights. It will alsoincrease the infiltration rate and reduction of water run-off. Improvedstructures are needed because weak soil and sand structure areproblematic in roads and highway slopes, embankments, water channels,construction excavation banks, landing sites such as civil and militaryair fields, sand dunes movement, military camps, oil fields andagriculture.

To overcome the above mentioned problems, extensive research on soilstabilization by chemical means was carried out and has been reported inthe literature. The various methods and chemical compositions reportedby various researchers on soft stabilization typically have one or twoobjectives. The first objective is to improve the soil structure and thesecond is to improve the load-carrying capacity. These objectives can beaccomplished by the addition of soft additives or soil conditioners orsoil modifiers. For example, there are chemicals that perform severalfunctions and provide significant advantages when added to soil. Some ofthese soft additives improve soft strength, aggregate stability andwater infiltration, while others limit water adsorption, soil erosion,water evaporation, water run-off, etc. To be effective, a soil additiveshould also be permeable to water to allow for plant growth thusincreasing water infiltration and minimizing water run-off. The soiladditive should also penetrate the pores of soft grains and stabilizesoil and prevent its erosion. Stabilizers should also be absorbed on theedges and surfaces of soil particles to cause bridging and promote interparticle linkages. Soft stabilizers should also provide strength to thetreated soft to withstand the impact of rain in heavy storms, wind andtraffic.

Therefore the ideal soil additive would be the one that can function formost soil types. The additive should be easily applied and easilydispersed in soil and it is preferred that it is water-soluble and canbe easily sprayed rather than being mechanically mixed with the soil.One important requirement of soil additives is that they should be oflow cost and economical. Another important consideration is that soiladditives should be environmentally friendly and last long enough toallow for vegetative growth. In addition, it should not to beaccumulated in the soil for long periods, and hence, should bedegradable.

Notwithstanding the above, there are problems associated with existingcommercial soil conditioners. First, some are expensive and are noteconomical to use (e.g., polyacrylamides, hydrolyzed polyacrylonitriles,vinyl acetate-maleic anhydrides, polyvinyl alcohols, polyvinyl acetates,acrylic polymers, styrene-butadiene, polyurethanes, etc.) Others are notacceptable and do not allow water infiltration in the ground becausethey are hydrophobic or they form a film that is impermeable to water,when sprayed on top of the soft (e.g., Bitumen, asphalts, polyvinylacetate, polyurethane, etc. ) Still others are of limited use and onlyprovide one or two functions. For example, styrene-butadiene providesstability to the soil, yet it does not provide any appreciable strength.Stabilizers of this category include bitumen and asphalt andurea-formaldehyde. Other additives may be toxic like those organicsolvent-based additives, e.g., polyurethanes, and polyacrylamides thatrelease the acrylamide toxic monomer and chromium lignosulfonates thatrelease toxic chromium which has been banned in some countries.

Work on soil stabilization of sand with aqueous urea-formaldehyde resinshas been carried out. For example, slow release fertilizers ofurea-formaldehyde resins with ratios of urea to formaldehyde of 2.5 to 3were shown to be suitable materials for improving sand structures.Addition of K₂ SO₄ to slow release fertilizers of urea-formaldehyde withratios of urea-formaldehyde 3 and K₂ O/N=1 was characterized by a highwater-holding capacity. Sandy soils were also consolidated by the use ofurea-formaldehyde resins with cross-linking agents in order to preventthe urea-formaldehyde resins from leaching through the sand bydecreasing its solubility to zero. For instance, sandy soils wereconsolidated and hardened by the use of urea-formaldehyde resins withvarious proportions of HCI, alum and p-toluene sulfonic acid ascross-linking agents. The injection of urea-formaldehyde resins with asolution of H₂ SO₄ as cross-linking agent into sandy soil gave acompressive strength of 25 kg/cm². Similarly treatment of sandy soilwith urea-formaldehyde resins using 9% based on the weight of soiltogether with calcium hydrogen phosphate monohydrate as cross-linkingagents gave a compressive strength from 114 to 120 kg/cm². The cold andhot curing of urea-formaldehyde resins in sandy soil was examined andfound that the optimum contents of urea-formaldehyde resins was 10 and20% based on the weight of sand with compressive strength of 13.0 and25.0 kg/cm² respectively.

Aqueous urea-formaldehyde resins have been used with metal sulfate,nitrate, carbonate, phosphate, and chloride together with H₂ SO₄ ascross-linking agents for strengthening sandy soil. For example, aqueousurea-formaldehyde resin mixed with KCI and NH₄ Cl gave a compressivestrength of 18.6 kg/cm², CaCl₂ and NH₄ OH gave a compressive strength of28.5 kg/cm² ; with NACl, gave a compressive strength of 13.0 kg/cm².Also urea-formaldehyde resins containing adducts of urea-H₂ SO₄, urea-H₃PO₄ or urea-HNO₃ gave a compressive strength of about 25.0 kg/cm² wheninjected into sandy soils.

It has been found that the water resistance and stability of swellingsoil aggregates were increased by treatment with an aqueous solution ofurea-formaldehyde resin at 0.8-1.2% of the weight of the soil which wasfollowed by incorporation of an aqueous solution of polyacrylic acid at0.04-0.3% of the weight of the soil. Also aqueous solutions containingurea-formaldehyde resin and polyvinyl alcohol (PVA) in a ratio of 1:1.5was found to stabilize the water permeable soil when added in a range of0.5-1.0 by weight of sand with an acid solution as curing agent.

Chemical modification of urea-formaldehyde resins has also beensuggested for sand stabilization, for instance copolymers ofurea-phenol-formaldehyde resins with a viscosity of 8.6 cP was used forstrengthening sandy soil when added in an amount of about 7.5% based onthe weight of sand to give a compressive strength of 47 kg/cm². It hasalso been reported that copolymers of urea-furfural-formaldehyde resinsgave a compressive strength of 37.0 kg/cm² when added in an amount of 5%based on the weight of sand.

Despite the voluminous research that has been reported on the use ofurea-formaldehyde as soil stabilizers, serious drawbacks exist. As canbe seen from the above, high application rates of urea-formaldehyde areneeded to obtain reasonable load-carrying capacity for the treated soil.These application rates make this class of materials uneconomical. Inaddition when urea-formaldehyde resins are being used as soilstabilizers in the powder form, it is difficult to apply, and they tendto dry moist soil and make the soil difficult to compact. In additionurea-formaldehyde stabilize only a limited number of soil types.

The use of sulfonated amino formaldehyde, a polyanionic condensates, assoil stabilizers was disclosed in U.S. Pat. No. 4,793,741. Thesepolyanionic polymers were used in combination with polyvinyi alcohol tostabilize Gatch type soil. The effect of such compositions on sandysoils like dune sands is significant. However, polyvinyl alcohol isexpensive and is difficult to dissolve in water.

Therefore an object of this invention is to provide a method ofstabilizing poorly bonded soils that are difficult to be aggregated likebeach and dune sands. Another object of this invention is to provide acomposition and a method for significantly improving the load-carryingcapacity of such soils. Still a further object to this invention is todisclose a composition that is relatively free of the drawbacksmentioned above. Yet another object is to provide a relativelyinexpensive and economical and an environment-friendly, easy to handleand easy to apply stabilizing chemical composition. Still another objectis to provide a multipurpose chemical composition that acts as afertilizer and a soil stabilizer.

SUMMARY OF THE INVENTION

The present invention contemplates a water-soluble polyanioniccomposition including a sulfonated urea-melamine formaldehydecondensate, a non-ionic water soluble resin such as urea-formaldehydecondensate, a water soluble salt like the basic salt of sodium borate,and neutral salts like potassium dihydrogen phosphate, potassium nitrateand sodium chloride and other inorganic materials like sodiummontmorillonite and the like. An aqueous solution of this composition issprayed onto the surface of the soil or mechanically admixed therewithto improve the load-bearing capacity of the treated soil. The treatmentwill also improve the resistance of the treated soil to erosion by wateror wind, and in addition, the composition provides basic plant nutrientsof nitrogen potassium and phosphorous and conditions the soil to make itmore favorable for plant growth.

The compositions disclosed herein can be sprayed on the top of the soilby conventional equipment. Since the compositions have low viscosity,the aqueous solution penetrates the pores and forms strong interparticle linkages and forms strong bridges. These strong linkages arerealized, because of the polyanionic nature and dispersing power of thesulfonated urea-melamine-formaldehyde polymer which coats and impartsnegative charges to the soil particles resulting in reordering of thesoil matrix. In addition, the aggregating power of urea-formaldehydecondensates causes the aggregation of various particles by beingadsorbed on the surfaces of the soil grains and ties the variousparticles together. The other additives disclosed in this compositionhave specific functions of completing and perfecting the intra- andinter particle linkages by providing more reaction sites and cross-linkthe various components of the chemical composition in the soil matrix.Therefore, the collective action of the various components of thisstabilizing chemical composition results in a strong soil matrix whichresists erosion by water and wind and which can sustain greater loads.Therefore, the stronger soil matrix resists the erosion power resultingfrom the kinetic energy of failing rain drops especially in the case ofthunderstorms.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS OF THE INVENTION

The process for soil stabilization and conditioning, according to thepresent invention, wherein an aqueous solution is applied to the surfaceof the soil includes the following steps.

A polymeric solution is made by mixing an aqueous formaldehyde solutionhaving a concentration ranging from about 30-50% at a temperature ofbetween 70°-90° C. and a pH of about 10 to 12 with a urea-melamine resinso that the molar ratio of formaldehyde to urea-melamine is in the rangeof 2.5:1 to 4.5:1. The mixing is continued until all of theurea-melamine resin dissolves.

A sulfonating agent such as an alkali metal sulfite, bisulfite ormetabisulfite is added to provide a molar ratio of sulfite group to theurea-melamine in the range of 0.8:1 to 1.2:1 and the resultingsolution's temperature is maintained at about 70° to 90° C. for a periodof 20 to 300 minutes.

The pH of the solution from the previous paragraph is then adjusted toabout 2.5 to 4.0 by adding an inorganic acid, and the reactantspolymerized for a period of 30 to 150 minutes.

The pH of the polymerized solution is then adjusted to about 7-9 byadding an alkali metal hydroxide and the solution temperature ismaintained between 70° to 90° C. for about 30 to 150 minutes.

The resulting solution is cooled down to room temperature and itsviscosity and solid contents are measured and recorded. This is referredto as component A of the stabilizing composition.

Urea-formaldehyde condensates are then prepared by adding urea to waterand heating the solution to about 70°-90° C. Then the pH is adjusted to8-10 by the addition of an alkali metal hydroxide. A formaldehydeaqueous solution having a concentration ranging from about 30-50% isthen added. The amount of urea to formaldehyde in this step is 1:5 to1:6. After the addition of formaldehyde the pH drops to 5-6 and is thenraised to 8-9 by the addition of an alkali metal hydroxide. The mixtureis heated for 25-45 minutes to get the temperature back to 70°-90° C.This is the first step of the reaction procedure where the pH is about7-8 and the temperature is between about 70°-90° C.

The second step involves lowering the pH of the solution down to 4-5 bythe addition of an inorganic acid. The reaction then continues for 25-45minutes. The solution is then neutralized by the addition of an alkalimetal hydroxide and an amount of urea is added immediately to thereaction solution. The amount of urea added is such that the overallmolar ratio of urea to formaldehyde is 1:2 to 1:3. After 5 to 10 minutesof the addition of urea, the pH of the solution is between 6 and 7 whilethe temperature is about 70°-80° C. At this point formic acid is addeduntil the pH is within the range of 4-5 and the temperature is between95° to 105° C. The reaction continues from 20 to 60 minutes at theseconditions after which the pH is raised to about 8-9 by the addition ofan alkali metal hydroxide.

The resulting solution of urea-formaldehyde condensates is cooled andits viscosity and solid contents are measured and recorded. Thissolution is referred to as component B of the stabilizing compositionwherein the solid contents range between 40-70% and the viscosities whenmeasured at 20° C. range between 500 to 6500 cP.

The solution of component B has the characteristics of a slow releasefertilizer where preparations with higher viscosities gave lower valuesof free urea when they were hydrolyzed. For example after about 50minutes of urea-formaldehyde hydrolysis, the amount of free ureareleased from a solution of urea-formaldehyde having a viscosity of 560cP was about 18×10⁻³ gm urea/gm urea-formaldehyde compared to aurea-formaldehyde solution having a viscosity of 2500 cP where thereleased free urea upon hydrolysis was only 9×10⁻³ gm urea/gmurea-formaldehyde which is half the amount of the 560 cP solution.

Gel Permeation Chromatography (GPC) technique was used to measure theweight average molecular weight ( Mw) and the average number molecularweight ( Mn) for the urea-formaldehyde polycondensates. The preparationswith viscosities of 885 cP, 1423 cP, 2236 cP and 3050 cP have (Mw's,Mn's) of (4400, 870), (5330, 820), (6840, 950) and (7350, 930)respectively with MwE,ovs Mn of 5.1, 6.5, 7.2 and 7.9 respectively. Itis obvious that as the degree of polymerization increases thepolydispersity increases and the sample has broader distribution.Therefore the fraction of the low and high molecular weight species canbe controlled by the reaction conditions and this will affect theirperformance as an integral component in the stabilizing chemicalcomposition as well as their slow release characteristics.

The solution of component B is added to the solution of component A toform a soil stabilizing mixture or composition. To this mixturecomposition and depending on the end application of these compositions,a number of inorganic solutions containing basic salts like di-sodiumtetra borate, sodium carbonate, sodium sulfite, and others butpreferably di-sodium tetra borate are added. Other additives includesolutions of neutral salts like sodium chloride, sodium nitrate, sodiumsulfate, potassium nitrate, potassium chloride, potassium di-hydrogenorthophosphate and others but preferably sodium chloride and potassiumnitrate and potassium dihydrogen orthophosphate. Additional additivescan also be added, such as ammonium phosphate, phosphoric acid,tri-potassium phosphate, triethyl phosphate, di-phosphorous pentoxide,nitrogen, potassium and phosphorous ("NPK") complexes and others likecarboxymethyl cellulose and the like and sodium montmorillonite clay andother clay containing soils like Marl soils and others. The compositionso formed can be applied to the soil either by spraying them on top ofthe soil with conventional spraying equipment or by mechanically mixingthem with the soil. Further the composition with various ingredients canbe applied to the soil as an integrated solution in the aqueous phase orin the powder form or in combinations thereof. The compositions can beapplied in any concentration ranging from 1 to 15% with an applicationrate ranging from 0.2% to 2% by weight of sand in case of mechanicalmixing or from 5 to 250 gm/m² of treated soil in case of top soilspraying.

In addition the ratio of urea to melamine plus urea in the sulfonatedurea-melamine formaldehyde should range between 0.1 to 1.0:1.0 andformaldehyde to urea plus melamine ranges between 2.5 to 4.5:1.0 and themolar ratio of sulfite group to the urea plus melamine should be in therange of 0.8 to 1.2:1.0. The weight ratio of urea-formaldehyde in thestabilizing mixture ranges between 10% to 90% but preferably between 20%and 70%. The weight ratios of other inorganic salts ranges between 0.2%to 10%.

The following examples will further illustrate the invention but are notto be construed as limiting its scope.

EXAMPLE 1

130 grams of 37% formaline solution were heated with 400 gm of water at80° C. for 10 minutes at a pH of 10. To this solution 12.6 gm ofmelamine and 24 gm of urea were added simultaneously. The reactionmixture continued to react for 15 minutes at a pH of about 10 and atemperature of about 80° C. After all the urea and melamine dissolvedcompletely, 38 gm of sodium metabisulfite were added and the pH andtemperature were maintained at the same values of 10 and 80° C.respectively. The reaction continued for 60 minutes. Then the pH of thereaction mixture was lowered to 3.5 by the addition of sulfuric acid.The reaction continued at this pH and 80° C. for another hour. The pH ofthe solution was then raised to 9 by the addition of sodium hydroxideand the reaction continued for forty minutes at the same temperature of80° C. After cooling to room temperature the viscosity was measured at25° C. to give a value of 1.86 cP. The solid contents were 22.3%. Theurea to urea-melamine was 0.8 to 1.0.

The above procedure was repeated for different percentages of urearanging from 0.0% to 100%. The viscosities obtained at 25° C. for 20%concentrated solutions with urea percentages of 20%, 40%, 60%, 80% and100% were: 4.38, 2.15, 2.0, 1.85 and 1.43 cP respectively.

EXAMPLE 2

A urea-formaldehyde polycondensate was prepared by adding 86 gm of ureato 100 gm of water. The solution was heated until its temperaturereached 80° C. The pH was adjusted to 8.5 by the addition of potassiumhydroxide. After the complete dissolution of urea, 627 gm of 37%formaline solution was added. The pH was maintained at 8.5 and thetemperature at 80° C. The reaction continued for 30 minutes. Then the pHwas brought down to 4.8 by the addition of sulfuric acid and thereaction continued for another 30 minutes. After that, the solution pHwas brought up to about 7 by the addition of potassium hydroxide and 100gm of urea were then added. After complete dissolution of urea, formicacid was added to bring the pH down again to 4.7. The reaction mixturecontinued to react for a certain time depending on the desired viscosityof the product. After a reaction time of 30 minutes the pH was raised to8 by the addition of potassium hydroxide. The solid contents of thefinal mixture was 45%. The viscosity at 23° C. was 7.85 cP.

EXAMPLE 3 "Compressive Strength Test"

For compressive strength tests of soil, cylindrical specimens of 5 cmdiameter and 10 cm long were prepared according to the followingprocedure. For a control specimen of dune sand, 160 gm of water wereadded to 1350 gm of soil. After complete mixing the soil samples becamehomogeneous and wet. Samples were then cast in a mold in three equallayers. Each layer was compacted by a free fall of one kg of steel massfor 15 times. Three specimens are made for each test. After thespecimens were molded they were allowed to cure for 24 hours at roomtemperature followed by 24 hours at 70° C. Stabilized samples of dunesand were prepared by mixing 160 gm of the soil stabilizer compositionsolution with 8.5% solid concentration and the same procedure wasfollowed as set forth with respect to the control. The dried sampleswere then tested for compressive strength using an MTS 812 testingsystem at a rate of 0.67 cm/min. The average of three specimens arereported. The same procedure was used for other types of soil exceptthat different amounts of water were used. For example Marl B type soilneeded almost twice as much of fluid solutions to have the specimenshomogeneous and wet so they could be molded.

EXAMPLE 4 "Simulated Rain Test"

The Simulated Rain Test was used to test for the erosion resistance ofsoil according to the following procedure. 7 kg of soil were mixed with0.7 kg of water till they became a homogeneous wet mix. They were thencompacted in 30×30×5 cm square pans. Some of these pans were perforatedat the bottom to allow for water drainage and some are withoutperforations. The compacted samples were allowed to dry for 24 hours atroom temperature. To stabilize these samples, the soil stabilizercomposition was prepared in different dilution ratios. They were thensprayed on top of soil samples at a rate of 20-100 gm/m². They were thenallowed to dry at room temperature for 24 hours followed by 24 hours at70° C. The dried samples were placed in the Rain Simulator whichconsists of a 35×35×35 cm over head tank and capillaries fixed in thebottom of the tank. The capillaries produce water drops equivalent tonatural rain drops which is about 3 mm in diameter and they fall from aheight of 2.5 meters on top of the soil samples. The soil samples can bepositioned at an inclination ranging from 0.0 to 60 degree angles. Theeroded samples resulting from splashing and from water run-offs is thencollected and recorded. The rain fall intensity can be changed from 10mm to 50 mm/min.

EXAMPLE 5 "Water Run-off Test"

The soil sample preparations for the water run-off tests are similar tothose for the simulated rain tests. After the samples are dried, theyare placed on an inclined surface of 30 degree angle. Water is thenallowed to flow on top of the soil samples at a rate of 6 liters/min.for six continuous hours. At the end of the run, eroded soil was taken,dried and weighed to calculate its percentage from the original knownweight of the soil. The above test is repeated for three cycles wherethe sample is allowed to be cured between cycles.

EXAMPLE 6 "Wind Erosion Test"

The soil samples preparations for wind erosion test are the same asthose of Examples 4 and 5. The samples were then exposed to differentwind velocities ranging from 0.0 to 65 km/hr striking at an angle of 30degrees. The maximum wind velocity at which sand starts to be eroded wasthen recorded for different treatments at the onset of failure.

EXAMPLE 7

The three soil samples that were tested with the various soilstabilizers were: dune sand, Marl A soil and Marl B soil. The chemicalcomposition of these soils is shown in Table 1 below.

                  TABLE 1                                                         ______________________________________                                        Elemental analysis of the three soil samples                                  ANALYTE   DUNE SAND     MARL A   MARL B                                       ______________________________________                                        Al.sub.2 O.sub.3                                                                        3.41          2.82     1.49                                         BaO       0.03          0.02     0.11                                         CaO       5.77          15.60    23.57                                        F.sub.2 O.sub.3                                                                         0.68          0.68     0.45                                         K.sub.2 O 1.54          1.00     0.63                                         MgO       0.93          6.29     18.02                                        Mn.sub.2 O.sub.3                                                                        0.02          0.02     <0.01                                        Na.sub.2 O                                                                              1.16          0.72     0.29                                         SO.sub.3  0.93          4.43     2.54                                         SiO.sub.2 82.8          60.72    38.26                                        SrO       0.03          0.08     0.07                                         TiO.sub.2 0.20          0.15     0.09                                         ZnO       0.09          <0.01    <0.01                                        LIO*      3.80          8.10     15.03                                        ______________________________________                                         *loss of ignition                                                        

EXAMPLE 8

A resin solution was prepared in the same manner as in Example 1 wherethe mole fraction of urea to urea-melamine was 0.8 to 1.0. Doses of 0.0,1.0, 2.0 and 3.0% based on dry weight of sand were mechanically mixedwith dune sand in accordance with Example 3. The compressive strengthsof the soil samples were 0.2, 6.3, 18.7 and 32.7 kg/cm² respectively.The dune sand chemical composition is shown in Table 1.

EXAMPLE 9

A resin solution was prepared in the same manner as in Example 2. Dosesof this resin solution of 0.0, 1.0, 2.0, and 3.0% based on the dryweight of the sand were mechanically mixed with dune sand in accordancewith Example 3. The compressive strengths of the soil samples were 0.2,2.3, 7.4, and 19.2 kg/cm² respectively.

EXAMPLE 10

A resin solution mixture was prepared by combining equal amounts ofresin solutions of Example 8 and Example 9. Doses of the mixturesolution of 0.0, 1.0, 2.0, and 3.0% based on the dry weight of sand weremechanically mixed with dune sand in accordance with Example 3. Thecompressive strengths of the soil samples were 0.2, 9.5, 24.4, and 38.0kg/cm² respectively.

EXAMPLE 11

A resin solution was prepared in the same manner as in Example 1 wherethe mole fraction of urea to urea-melamine was 0.8 to 1.0. Doses of thisresin solution of 0.0, 0.65, 1.0, 1.3 and 4.0% based on dry weight ofsand was mechanically mixed with another type of soil called Marl A inaccordance with Example 3. The compressive strengths of the Marl A soilwere: 16.4, 22.3, 29.7, 33.2, and 52.8 kg/cm² respectively. The chemicalcomposition of Marl A is shown in Table 1.

EXAMPLE 12

A resin solution was prepared in the same manner as in Example 1 wherethe mole fraction of urea to urea-melamine was 0.8 to 1.0. Doses of 0.0and 1.2% by weight of dry sand was mechanically mixed with another typeof soil called Marl B in accordance with Example 3. The compressivestrengths of the Marl B soil were 7.1 and 11.3 kg/cm² respectively. MarlB soil has the chemical compositions shown in Table 1.

EXAMPLE 13

A resin solution was prepared in the same manner as in Example 1 andanother resin solution was prepared in the same manner as in Example 2.A mixture of equal proportion was made from those two preparations and adose of 0.0 and 1.0% by weight of dry sand was mechanically mixed withother types of soil called Marl A and Marl B in accordance with Example3. The compressive strengths for Marl A soil were: 15.4 and 20.2 kg/cm²respectively and for Marl B the compressive strengths were: 7.1 and 15.3kg/cm² respectively.

EXAMPLE 14

Resin solutions were prepared in the same manner as in Example 1 wherethe molar ratio of urea to urea-melamine ranged from 0.2 to 1.0:1.0.More specifically resin solutions with urea percentages of 20%, 40%,60%, 80%, 100% were made. A dose of 1.0% of each of these preparationsbased on dry weight of sand were mechanically mixed with dune sand inaccordance with Example 3. The compressive strengths of the soil sampleswere: 2.6, 3.1, 4.1, 5.9, and 2.0 kg/cm² respectively.

EXAMPLE 15

A resin solution was prepared in the same manner as in Example 2. Dosesof 0.0, and 1.0% based on dry weight of sand were mixed mechanicallywith soils type Marl A and Marl B and in accordance with Example 3. Thecompressive strengths for Marl A were: 15.4, and 16.9 kg/cm²respectively, and for Marl B: 7.1 and 12.5 kg/cm² respectively.

EXAMPLE 16

A resin solution was prepared in the same manner as in Example 1 wherethe molar ratio of urea to urea-melamine was 0.8 to 1.0. A dose of thisresin solution of 1.0% by weight of dry sand was mixed with dune sand,which had sodium borate of 0.1% by weight premixed with it, and inaccordance with Example 3. The compressive strength of the soil samplewas 5.7 kg/cm².

EXAMPLE 17

The same resin solution of Example 16 was mixed with dune sand at a doselevel of 1.0% by dry weight of sand except that sea water was usedinstead of fresh water. The compressive strength of the soil sample was7.6 kg/cm².

EXAMPLE 18

The same resin solution of example 16 was mixed with dune sand at a doserate of 1.0% by weight of sand except that sodium chloride was alsopre-mixed with sand at a dose level of 0.25% by weight of sand. Thecompressive strength of the soil sample was 8.7 kg/cm².

EXAMPLE 19

The same solution of Example 16 was mixed with dune sand followed byequal amounts of resin solution prepared in the same way as Example 2. Adose of 1.0% of each by weight of sand was mixed with dune sand and inaccordance with Example 3. The compressive strength of the soil samplewas 9.4 kg/cm².

EXAMPLE 20

Example 19 was repeated except that sea water was added to the solutionprepared according to Example 2. The compressive strength of this soilsample was 10.7 kg/cm².

EXAMPLE 21

Example 19 was repeated except that sodium chloride was added to thesoil at a dose of 0.25% by weight of dry sand and in accordance withExample 3. The compressive strength of this soil sample was 10.1 kg/cm².

EXAMPLE 22

Example 21 was repeated except that sodium borate was added instead ofsodium chloride at a dose of 0.1% by weight of dry sand and inaccordance with Example 3. The compressive strength of this soil samplewas 13.7 kg/cm².

EXAMPLE 23

Example 22 was repeated except that sea water was added with thesolution mixture. The compressive strength of this soil was 17.2 kg/cm².

EXAMPLE 24

Example 22 was repeated except that potassium nitrate and potassiumdihydrogen phosphate were premixed with sand at a dose of 1.0% for eachbased on weight of dry sand and in accordance with Example 3. Thecompressive strength of this soil sample was 29.3 kg/cm².

EXAMPLE 25

Example 24 was repeated except that phosphoric acid replaced potassiumdihydrogen phosphate. The compressive strength of this soil sample was23.4 kg/cm².

EXAMPLE 26

A resin solution was prepared in the same manner as in Example 2. A doseof 1.0% by weight of dry sand of this resin solution was mixed with adune sand that had premixed with it 0.1% by weight of sand of sodiumborate and in accordance with Example 3. The compressive strength ofthis soil sample was 2.5 kg/cm².

EXAMPLE 27

A resin solution was prepared in the same manner as in Example 2. A doseof 1.0% by weight of dry sand was mixed with 0.25% by weight of sodiumchloride and the whole mixture was mechanically mixed with dune sand andin accordance with Example 3. The compressive strength of this soilsample was 2.4 kg/cm².

EXAMPLE 28

Example 27 was repeated except that the resin solution which wasprepared according to Example 1 was used. The compressive strength was11.6 kg/cm².

EXAMPLE 29

A resin solution mixture was made by mixing equal amounts of resinsolutions prepared in the same manner as in Examples 1 and 2. A dose ofthis mixture of 2.0% by weight of sand was mixed with dune sand and inaccordance with Example 3. The compressive strength of this soil samplewas 17.3 kg/cm².

EXAMPLE 30

Example 29 was repeated except that sodium chloride was added to themixture solution at a dose of 0.25% by weight of sand. The doses of 1.0%and 2.0% of the mixture were mechanically mixed with dune sand and inaccordance with Example 3. The compressive strengths of these soilsamples were 9.1 and 18.9 kg/cm² respectively.

EXAMPLE 31

Example 29 was repeated except that sodium chloride was premixed withdune sand at a dose of 0.25% by weight of sand. A dose of 2.0% of thesolution was mixed with this dune sand and in accordance with Example 3.The compressive strength of this soil sample was 24 kg/cm².

EXAMPLE 32

Example 29 was repeated except that sodium borate was added to themixture solution at a dose of 0.1% by weight of sand. Doses of 1.0% and2.0% of the mixture by weight of sand were used with dune sand and inaccordance with Example 3. The compressive strength of these soilsamples were 9.2 and 17.9 kg/cm² respectively.

EXAMPLE 33

Example 29 was repeated except that sodium chloride and sodium boratewere added to the mixture solution at a dose of 0.1% each by weight ofsand. A dose of 1.0% of this mixture by weight of sand was used withdune sand and in accordance with Example 3. The compressive strength ofthis soil sample was 12.5 kg/cm².

EXAMPLE 34

Example 30 was repeated except that potassium nitrate and potassiumdihydrogen phosphate were also added to the mixture solution at a doseof 1.0% each by weight of sand. Doses of 1.0% and 2.0% of the mixturesolution by weight of sand were mixed with dune sand and in accordancewith Example 3. The compressive strengths of these soil samples were 6.8and 22.0 kg/cm² respectively.

EXAMPLE 35

Example 34 was repeated except that sodium chloride was replaced bysodium borate at a dose of 0.1% by weight of sand. Doses of 1.0% and2.0% of the mixture solution were used with dune sand and in accordancewith Example 3. The compressive strength of these soil samples were 6.4and 32.6 kg/cm².

EXAMPLE 36

Example 35 was repeated except that different doses were mixed with dunesand. Doses of 1.0%, 2.0%, 3.0%, 4.0%, and 4.5% by weight of sand wereused with sodium borate dose of 0.1%, and 0.25% of each of potassiumnitrate and potassium dihydrogen phosphate. The compressive strength ofthese soil samples were: 6.2, 18.5, 35.3, 56.2, and 64.8 kg/cm²respectively.

EXAMPLE 37

Example 35 was repeated except that sodium chloride was also added tothe mixture solution at a dose of 0.1% by weight of sand. A dose of 1.0%of the mixture by dry weight of sand was used with dune sand and inaccordance with Example 3. The compressive strength of this soil samplewas 6.9 kg/cm².

EXAMPLE 38

Resin solutions were prepared in the same manner as in Examples 1 and 2.A dose of 1.0% of each by weight of sand was mixed with dune sand thathad carboxymethyl cellulose dose of 0.1% by weight of sand and inaccordance with Example 3. The compressive strength of this soil samplewas 22.0 kg/cm².

EXAMPLE 39

A resin solution was prepared in the same manner as in Example 1. A doseof 1.0% by weight of sand was mixed with dune sand that had 0.1% byweight of sand of carboxymethyl cellulose and in accordance with Example3. The compressive strength of this soil sample was 15.7 kg/cm².

EXAMPLE 40

Example 39 was repeated except that bentonite was premixed with soilinstead of carboxymethyl cellulose. A dose of bentonite of 0.5% and 1.0%by weight of sand was mixed with dune sand and in accordance withExample 3. The compressive strengths of these soil samples were 12.6 and16.4 kg/cm² respectively.

EXAMPLE 41

Resin solutions were prepared in the same manner as in Examples 1 and 2.A mixture solution was made by adding equal amounts of those two resins.To a dose of 1.0% by weight of sand of this mixture was added 0.5% byweight of sand an NPK fertilizer mixture and 0.1% by weight of sand ofsodium borate. The whole mixture was mechanically mixed with dune sandand in accordance with Example 3. The compressive strength of this soilsample was 7.5 kg/cm².

EXAMPLE 42

Example 41 was repeated except that NPK solid fertilizer was replaced byliquid fertilizer of NPK: (20.0:20.0:20.0). The compressive strength ofthis soil sample was 8.2 kg/cm².

EXAMPLE 43

Control samples from dune sand were prepared in accordance with Example4. After the samples were cured at room temperature for 24 hours theywere dried at 70° C. for another 24 hours. The samples were then exposedto water run-off test in accordance with Example 5 and to simulatedrainfall test in accordance with Example 4 and to wind erosion test inaccordance with Example 6. The sand erosion from the water run-off testwas 2200 gm or 31.4% of total sand in just in the first 10.0 minutes oftesting. The erosion from rainfall test was 3037 gm or 43.4% of totalsand in just 30.0 minutes of exposure at a rainfall intensity of 12.48cm/hr. The wind speed at the onset of sand erosion was 13.5 km/hr. Theused dune sand particles sizes ranged from 0.15 to 0.21 mm in diameter.

EXAMPLE 44

Solution mixture of Example 30 was sprayed on top of dune sand at a rateof 3.5 l/m² and a dose of 50.0 gm/m² and in accordance with Examples 4and 5. After the samples were cured, they were exposed to water run-offfor six continuous hours after which there was no erosion. This test wasrepeated for another two six-hour cycles for the same sample afterproper curing after each cycle. Again there was no soil erosion. Thetest was repeated for different application rates of 20.0, 30.0 and 40.0gm/m². Samples with application rates of 30.0 gm/m² and higher showed noerosion of sand. However, erosion of 20.0 gm/m² treatment wassignificant where about 877 gm of sand or 12.5% of total sand was erodedin the first 10.0 minutes of the test. After the completion of the thirdcycle the sample with 50.0 gm/m² was then cured and exposed to simulatedrainfall test in accordance with Example 4. After an exposure of 60.0minutes under a rainfall intensity of 15.6 cm/hr., the erosion of soilby splash and water run-off were 67.4 gm or 0.96% of the total soil and265 gm or 3.78% of the total soil respectively. The overall soil losswas 332.4 gm or 4.75% of the total soil.

EXAMPLE 45

Example 44 was repeated for the solution mixture of Example 22. After anexposure of three six-hour cycles to water run-off according to Example5, there was no sand erosion. The sample was then cured and exposed tothe simulated rainfall test according to Example 4. After an exposure of60.0 minutes under a rainfall intensity of 13.9 cm/hr, the erosion ofsoil by splash was 45.3 gm or 0.65% of the total soil and from waterrun-off was 623 gm or 8.9% of the total soil.

EXAMPLE 46

Example 43 was repeated for a solution mixture of Example 25. The samplewith an application rate of 50.0 gm/m², was then exposed to thesimulated rainfall test in accordance with Example 4. The rain intensitywas 23.4 cm/hr falling over an area of 900 cm² for a total time of 35minutes. The eroded soil by splash and by water run-off was collectedand dried. 321 gm of total soft was eroded after 35 minutes ofcontinuous rain. This is about 4.6% of total soil at 13.65 cm ofrainfall. The infiltration rate was 205 ml/min. compared to waterrun-off rate of 350 ml/min. The splash erosion was responsible for about10.0% of the total soil loss when the soil pan was exposed at 30 degreeinclination with respect to the falling min.

EXAMPLE 47

Example 44 was repeated on dune sand that was treated with the solutionmixture of Example 35 at a rate of 100 gm/cm². After the sample wascured it was exposed to water erosion test in accordance with Example 5for three cycles of 36 min., 45 min., and 240 min. respectively. Thesoil eroded was: 98 gm or 2.8%, 55 gm or 1.6%, and 5.0 gm or 0.14%respectively. After the water erosion test was completed, it was curedand the sample was then exposed to simulated rainfall test in accordancewith Example 4. After an exposure of 60 min. to rainfall intensity of11.34 cm/hr the splash erosion was 48 gm or 1.39% of total sand and thewater runoff erosion was 289 gm or 8.1% of total sand.

EXAMPLE 48

Simulated rainfall test was conducted for dune sand treated withpolyvinyl alcohol PVA; Mwt=125,000! at an application rate of 22 gm/m²and in accordance with Example 4. After an exposure of 30 min. to arainfall intensity of 17.46 cm/hr, the splash erosion was 73 gm or 1.0%and the water run-off erosion was 569 gm or 8.1% of total sand.

EXAMPLE 49

Example 48 was repeated except that solution of Example 30 was sprayedon top of dune sand at a rate of 3.5 l/m² and a dose of 30.0, 75.0, and100.0 gm/m². After the samples were cured they were exposed to simulatedrainfall in accordance with Example 4. After an exposure of 30.0 min. toa rainfall intensity of 12.0 cm/hr, the splash erosion and water run-offerosion for treatment with dose of 75 gm/m² were: 51.0 gm and 268 gmrespectively. Similarly, the splash erosion and water run-off erosionfor treatment with dose of 100.0 gm/m² were: 45 gm and 205 gmrespectively. However, treatment with dose of 30.0 gm/m² was treateddifferently. First, it was subjected to water run-off test in accordancewith Example 5. After three 6-hour cycle of water run-off, there was noerosion, the sample was then cured and exposed to the simulated rainfalltest in accordance with Example 4. The splash erosion and water run-offerosion were 25.0 gm and 290.0 gm respectively for a rain intensity of13.87 cm/hr.

EXAMPLE 50

Dune sand was placed in 20.0 cm diameter circular trays in hump-likeshapes to simulate sand dunes. The trays were then sprayed with thesolution of Example 30 at a rate of 4 l/m² and an effective stabilizerdose of 0.0, 5.0, 10.0, 15.0, and 20.0 gm/m². The sprayed sand humpshave an estimated area of 0.036 m². One additional circular tray wassprayed with polyvinyl alcohol (PVA) of molecular weight of 125,000 at adose of 5.0 gm/m². Another circular tray was filled with dry dune sandand tested as is. After the trays were cured they were exposed to winderosion test in accordance with Example 6. The wind speeds at whicherosion of sand started to occur were: 13.5 km/hr for the untreated sand(control), and 53.5 km/hr for the PVA treatment. The other treatments ofdoses of 0.0, 5.0, 10.0, 15.0, and 20.0 gm/m² had onset of erosion atwind speeds of: 40.0, 51.0, 58.0, 59.0, and 60.0 km/hr respectively.

The previous Examples are presented to illustrate the preferredembodiments of the present invention. For example, Examples 1 and 2present the detailed chemical preparation procedure of the two maincomponents of the chemical composition of this invention. Examples 3 to6 present the tests used to evaluate the performance of the variouscompositions and their effect on different soil types. Elementalanalysis of some of the tested soils is presented in Table 1 of Example7. This table shows the wide variations in the chemical composition ofthese soils. Of particular interest is the concentration of silicondioxide and calcium oxide, where silicon dioxide ranges between about38% for Marl B to about 83% for dune sand, while calcium oxide rangesbetween 24% for Marl B to about 6% for dune sand. This wide variation inchemical composition allows for a true test of the versatility andeffectiveness of the new compositions.

Examples 8 and 9 show the effect of the main two components (i.e.component A, which is a sulfonated urea-melamine-formaldehydecondensate, and component B, which is a urea-formaldehyde condensate),on the compressive strength of dune sand when these components are usedas separate entities. However, these components show superiorperformance when they are used together, as one integral mixture, as canbe seen from Example 10 and Examples 8 and 9. For example, a dose of 1%of the mixture with dune sand improves its compressive strength by atleast 50% compared to the samples that were treated with component Aalone (Example 8) and up to about 400% compared to the samples treatedwith component B alone (Example 9).

Examples 11, 12, 13, and 15 show that the composition mixture and itscomponents have a significant effect on all types of soil. For example,an application dose of 1.0% by weight of sand of each of the compositionmixture, component A, and component B improve the compressive strengthof dune sand by a factor of: 47.5, 31.5, and 11.5 respectively and theimprovement of Marl A by a factor of: 1.3, 1.8 and 1.1 respectively andthe improvement of Marl B by a factor of: 2.15, 1.59 and 1.76respectively.

Example 14 demonstrates the effect of the percent of urea in thecomposition of component A on the performance of this component inimproving the compressive strength of the treated dune sand. From aneconomical and agronomical point of view, it is desirable to have a highpercentage of urea in the composition, because urea is among thecheapest commodity chemicals and it is the main source of nitrogen forplants. Example 14, therefore, shows that the optimum percentage of ureafor improving the compressive strength of the treated sand is about 80%.This makes this product very economical. Also in addition to its mainfunction as a soil stabilizer and conditioner this product is asignificant source of nitrogen for plants.

Examples 16 to 40 are presented to demonstrate the effect of otheradditives on the stability of the soil. In addition, these examplesillustrate the effect of the method of application in terms of:application rates, application procedures and the order of addition ofthe various components to the soft to be treated. These examples help toestablish the optimum procedure and preparation conditions in order toprepare the optimum chemical composition. They also help to establishthe optimum methodology of applying the claimed chemical compositions tostabilize various soils.

To illustrate further, Examples 19 and 22 demonstrate clearly the effectof sodium borate additive in improving the compressive strength of dunesand by about 50%.

Examples 20 and 21 show the effect of sea water and calcium chloridewhich improve the compressive strength by about 10%. The addition ofpotassium nitrate and potassium dihydrogen phosphate to dune sandimproves its strength by about 200% as can be seen from Examples 22 and24. Phosphoric acid and potassium nitrate improve the compressivestrength of dune sand by about 70% as can be seen from Examples 22 and25.

Examples 19 to 25 show the improvement in compressive strength of thetreated dune sand when the various composition constituents are added toit in separate entities. However, more significant effects can berealized if these components are combined together in one integralcomposition as illustrated in Examples 29 to 37.

Example 29 shows an advantage of 84% over Example 19. In Example 19,dune sand was treated with component A and component B as separateentities, while in Example 29, the dune sand was treated with a combinedcomposition of component A and B. Moreover, the addition of the otherproposed additives to this combined composition as one integralcomposition enhances its effectiveness as a stabilizing chemicalcomposition. For example, the addition of sodium chloride with thestabilizing mixture improves the compressive strength of sand by almosta factor of two or more as can be seen from Examples 21, 30 and 31.Similarly the addition of sodium borate to the mixture results in 30%improvement in compressive strength as can be seen from comparingExamples 22 and 32. The addition of potassium nitrate and potassiumdihydrogen phosphate to the mixture also improves the compressivestrength very significantly as can be seen from Examples 34 to 37.Finally, other additives can also be added to the mixture and thisresults in significant improvements in compressive strengths.Carboxymethyl cellulose and sodium montmorillonite (i.e., bentonite)effects are presented in Examples 38, 39, and 40 where significantimprovements in compressive strengths are realized.

Examples 43 through 50 demonstrate the effectiveness of the stabilizingcomposition of this invention in stabilizing dune sands againstsimulated natural weathering factors like erosion by water run-off,rainfall, and winds. The effect of these three factors on untreated dunesands (i.e., controls) is shown in Example 43 where severe erosion ofsand can be seen taken place in a very short time of testing. Forexample, the erosion caused by water run-off was reduced from 2200 gmfor the control sample to zero gm when the sand sample was treated withas low as 30 gm/m² of the disclosed chemical composition as can be seenfrom Examples 43 and 44. Similarly the erosion caused by the kineticenergy of rainfall drops was reduced from 3037 gm for the control toabout one tenth of that when the samples were treated with about 50gm/m² of the composition of this invention as can be seen from Examples43, 44, 45, and 46. The effectiveness of these compositions against winderosion is illustrated in Examples 43 and 50, where the onset of erosionthat took place at wind speeds of about 13.5 km/hr for the controlsamples have been improved to more than 50 km/hr with a treatment withmy composition as low as 5 gm/m² as demonstrated by Examples 43 and 50.Finally comparison of the performance of the presently disclosedchemical compositions versus well publicized and recommended commercialstabilizing agent, polyvinyl alcohol, which is very expensive comparedto the disclosed material, is shown in Examples 46, 48, and 50. Example46 and 48 show the sand erosion by rainfall is twice as much when thesand is treated with polyvinyl alcohol than when it is treated with mycompositions. Example 50 also shows that the disclosed material is justas effective in stabilizing sand as polyvinyl alcohol at the dose levelof 5 gm/² for both treatments. However, the presently disclosed materialis about four times cheaper than polyvinyl alcohol.

While the examples have been limited to urea and melamine as arepresentative amine compound, it is obvious that other amines andpolyamines can also be used. However, urea is preferred since it iscommodity and relatively inexpensive. Similarly, other aldehydes may beused in place of formaldehyde, but formaldehyde is preferred for thosetypes of products and applications.

While the invention has been described in connection with its preferredembodiments, it is be recognized that changes and modifications may bemade therein without departing from the scope of the appended claims.

What is claimed is:
 1. A water soluble chemical composition for use as asoil stabilizer, conditioner and structuring agent comprising sulfonatedurea-melamine formaldehyde condensate, a urea-formaldehyde condensatehaving a weight average molecular weight (Mw) ranging from about 4400 toabout 10,000 and polydispersity (M_(w) /M_(n)) of 2.5 to 10, and aninorganic salt selected from the group consisting of di-sodiumtetraborate, sodium carbonate, sodium sulfite, sodium chloride, sodiumnitrate, sodium sulfate, potassium nitrate, potassium chloride,phosphoric acid, and potassium di-hydrogen orthophosphate, and mixturesthereof, and wherein the ratio of urea-formaldehyde to sulfonatedurea-melamine-formaldehyde is between 0.2:1 to 2.0:1 and saidcomposition having a solids content of between 1-15%.
 2. A water solublechemical composition for use as a soil stabilizer, conditioner andstructuring agent according to claim 1 which includes a materialselected from the group consisting of di-sodium tetraborate, sodiumchloride, potassium nitrate, phosphoric acid and potassium di-hydrogenorthophosphate.
 3. A water soluble chemical composition according toclaim 1 wherein the molar ratio of formaldehyde to urea-melamine in thesulfonated urea-melamine formaldehyde component is in the range of 2.5:1to 4.5:1.0.
 4. A water soluble chemical composition for use as a soilstabilizer, conditioner and structuring agent according to claim 1wherein the overall molar ratio of formaldehyde to urea in theurea-formaldehyde component is in the range of 2:1 to 3:1.
 5. A watersoluble chemical composition according to claim 1 which includes asulfonating agent selected from the group consisting of alkali metalsulfite, bisulfite and metabisulfite in an amount to provide a molarratio of sulfite to urea-melamine in the sulfonated urea-melamineformaldehyde component in the range of 0.8:1 to 1.2:1.0.
 6. A watersoluble chemical composition according to claim 1 wherein the molarratio of urea to urea-melamine is in the range of 0.2:1 to 1.0:1.
 7. Amultipurpose soil stabilizing and conditioning composition prepared by aprocess which includes the following steps:(a) forming a polymericsolution by adding a urea-melamine resin to an aqueous formaldehydesolution having a concentration from about 30-50% at a temperature ofbetween 70°-90° C. and a pH of about 10 to 12 so that the molar ratio offormaldehyde to urea-melamine is in the range of 2.5:1 to 4.5:1 andmixing until all of the urea-melamine resin dissolves; (b) adding analkali metal sulfite, bisulfite or metabisulfite to the polymericsolution of paragraph (a) to provide a molar ratio of sulfite group tothe urea-melamine in the range of 0.8:1 to 1.2:1 and maintaining theresulting solution temperature at about 70° C. to 90° C. for a period of20 to 180 minutes; (c) adding an inorganic acid to the solution fromstep (b) to thereby adjust the pH of the resulting solution to about 2.5to 4.0 and allowing the reactants to polymerize for a period of 30 to150 minutes; (d) adjusting the pH of the polymerized solution from step(c) to about 7-9 by adding an alkali metal hydroxide and maintaining thesolution temperature at between 70°-90° C., for about 30 to 150 minutesto thereby form a component; (e) forming a urea-formaldehyde condensateby adding urea to water and heating up the solution to about 70°-90° C.and adjusting the pH to 8-10 by the addition of an alkali metalhydroxide; (f) forming an aqueous formaldehyde solution having aconcentration from about 30-50% and adding the aqueous formaldehydesolution to the solution from (e) so that the amount of urea toformaldehyde is 1:5 to 1:6 to thereby drop the pH to 5 to 6 and thenadjusting the pH to 8-9 by the addition of an alkali metal hydroxide andheating the resulting solution for 25-45 minutes to bring thetemperature to between 70°-90° C. and the pH within the range of 7-8;(g) dropping the pH of the reaction solution obtained in (f) to between4 and 5 by the addition of an inorganic acid, allowing the reaction tocontinue for 25-45 minutes and then neutralizing the solution by addingan alkali metal hydroxide and thereafter adding an amount of urea in anamount such that the overall molar ratio of urea to formaldehyde is 1:2to 1:3 and allowing the pH of the solution to reach between 6 and 7while the temperature is about 70°-80° C.; (h) adding formic acid to thesolution of (g) to drop the pH to about 4-5 and allowing a reaction tocontinue from 20 to 60 minutes until the temperature is within the rangeof 95° to 105° C. and subsequently adding an alkali metal hydroxide toraise the pH to between 8 and 9; (i) adding the solution obtained in (h)to the solution obtained in (d) and adding a salt selected from thegroup consisting of di-sodium tetraborate, sodium chloride, potassiumnitrate, phosphoric acid and potassium di-hydrogen orthophosphate, andmixtures thereof, to thereby form an intermediate composition having aratio of urea-formaldehyde to sulfonated urea-melamine-formaldehyde ofbetween 0.2:1 to 2.0:1; and wherein a solution produced herein has asolid content of between 20 and 45%; and (j) diluting the compositionwith water to a solid content of 1 to 15% to form the multipurpose soilstabilizing and conditioning composition.